﻿//
// Copyright (c) 2011 Canyala Innovation AB
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and 
// associated documentation files (the "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
// copies of the Software, and to permit persons to whom the Software is furnished to do so, 
// subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT 
// NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH 
// THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 
//

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;

using Canyala.Lagoon.Extensions;

namespace Canyala.Lagoon.Presentation
{
    public interface IViewModel
    {
        IViewModel Parent { get; }
        void NotifyChanged(string name);
    }

    public class ViewModel<TRoot,TParent> : IViewModel, INotifyPropertyChanged
        where TParent : IViewModel
        where TRoot : IViewModel
    {
        public event PropertyChangedEventHandler PropertyChanged;
        protected readonly dynamic State;
        public readonly TParent Parent;
        
        public ViewModel() 
            { State = new PropertyManager(this); }

        public ViewModel(TParent parent) : this() 
            { Parent = parent; }

        public void NotifyChanged(string propertyName) 
            { 
                if (PropertyChanged != null) 
                    PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); 
            }

        IViewModel IViewModel.Parent
            { get { return this.Parent; } }

        public TRoot Root
        {
            get
            {
                IViewModel model = this;
                while (model.Parent != null)
                {
                    if (model.Parent is TRoot)
                        return (TRoot) model.Parent;

                    model = model.Parent;
                }

                if (!(model is TRoot))
                    throw new InvalidCastException("Root is not a {0} but a {1}".Args(typeof(TRoot).Name, model.GetType().Name));

                return (TRoot) model; 
            }
        }
    }
}
